Unity for Democrats But Not Republicans: The Temporal Dynamics of Intra-Party Bias in U.S. Electoral Politics

Abstract

Political identification is strong, stable, and the basis of enduring conflict, suggesting that attitudes towards candidates and their supporters will be difficult to change. Here, however, we show that the shift from party primaries (characterized by intra-party conflict) to the general election (characterized by inter-party conflict) can cause identities to be reconfigured - animosities between supporters of rival primary candidates can attenuate as superordinate goals (defeat rival party) and superordinate identities (Democrat/Republican) come to the fore. We provide a fine-grained account of these temporal dynamics by collecting data weekly from mid-June to early September 2016 (total N = 2,183), examining prosocial giving between supporters of competing primary candidates recruited from the online labor market Amazon Mechanical Turk. At the outset of our study, both Democrats and Republicans showed intra-party bias: that is, they shared more money with people from their own party who supported the same primary candidate compared to members of their own party who supported a different primary candidate. This in-group bias among Democrats remained high until the Democratic National Convention, and then disappeared entirely shortly thereafter. Bias among Republicans, conversely, existed at a high level both before and after, but not during, the conventions. These findings emphasize both the discontinuity and contingency of changing identities. The abrupt elimination of bias among Democrats, but resurgence of bias among Republicans, suggests that a superordinate goal of defeating the other party (which was salient for both sides during the shift to the general election and was particularly emphasized during party conventions) was not sufficient to bring supporters of different primary candidates together for a sustained period. Rather, sustained change may require successful efforts to emphasize shared (superordinate) party-based identity – a task which our data suggest the Democratic National Convention succeeded in achieving.